Wireless power transfer (WPT) is an emerging technology that has proven to be effective for charging vehicles, such as electric vehicles (EVs). In a typical WPT setup for EVs, a ground-based charging coil is supplied power, thereby inducing a current remotely in a second, vehicle-based coil located at the bottom of the EV.
No standard yet exists with respect to EV configurations and many EVs vary in several aspects from each other when it comes to the battery configurations, power levels, charging rates, and so on. Often, these can vary across different makes and models. Such variations can also be due to model year changes and different options. For example, one vehicle model may be fitted with large, expensive coils and a battery management system (BMS), to enable faster WPT charging. In contrast, a budget version of the same model may be equipped with a standard set of coils and a BMS that supports a lower rate charging. In other words, it is envisioned that different EVs in the future will have different WPT charging capabilities.
In addition, as battery wears out, the rate and level at which the battery can absorb energy may change. Therefore, the age and number of charge/discharge cycles a battery pack has gone through will also play a role in the power transfer capability and efficiency. A common charging infrastructure that will encounter a large variance of these scenarios will need to be capable of handling these variations and still be able to operate optimum level of efficiency.